In many applications, there can be two or more components in contact. Relative motion between such components can result in excessive wear of the components. Such component wear can ultimately affect the proper functioning of the components and the system or assembly of which they are a part.
Wear can be controlled within acceptable levels in some instances by the use of lubricants, by material selection and/or by design features that limit the motion and/or geometry of the components. However, there are many instances in which relative motion cannot be eliminated, such as in brake linings, gears, sliders and slip fits; wear is unavoidable in such cases. The extent of the wear and the suitability of the component for continued service are typically determined by visual and/or dimensional inspection. In some applications, wear indicators have been developed. For example, in the context of brake linings, wear limit notches or “squealers” can provide an audible warning that a certain amount of wear has occurred.
However, there are many applications in which regular inspection is not feasible because of a number of factors including, for example, time, labor, cost and disruptions due to down time. Thus, there is a need for a system that can monitor the wear of a component while the component is in operation or without having to remove the component from its operational position.